'The biggest Scalextric set in the game!' Inside huge Royal Mail distribution hub the size of SIX football pitches where 4.2million Christmas letters and parcels are posted on busiest day of the year (42 Pics)

Royal Mail shipped 4.2million letters and parcels in 24 hours on its busiest day of 2018 at hub in Slough Worldwide Distribution Centre n...

• Royal Mail shipped 4.2million letters and parcels in 24 hours on its busiest day of 2018 at hub in Slough
• Worldwide Distribution Centre near Heathrow employs thousands of people to sort huge amount of mail 
• 2018 is said to have been the most popular year in the hub's 15 year history to send letters and gifts 
• Staff have discovered everything in the post on the site, from dangerous snakes to hand grenades